Mycotoxin Development in Cashew Apple-Wheat Flour Composite During Tropical Storage

Area of Science:

• Food Science and Technology
• Mycotoxicology
• Agricultural Valorisation

Background:

• Ghana produces significant cashew but underutilizes cashew apples, contributing to food waste.
• Cashew apples are edible fruits with potential nutritional benefits.
• Mycotoxin development in food products is a major food safety concern, especially in tropical climates.

Purpose of the Study:

• To assess mycotoxin development in cashew apple-wheat composite flour during tropical storage.
• To evaluate the impact of varying cashew apple flour substitution levels (5%, 10%, 15%) on storage stability.
• To determine the safety implications for bread production from these composite flours.

Main Methods:

• Preparation of cashew apple-wheat composite flours at 5%, 10%, and 15% substitution levels.
• Storage of flour blends under ambient tropical conditions (25°C, 65% RH) for 14 days.
• Monitoring of moisture content, fungal growth (CFU/g), and aflatoxin B1 levels using AOAC and ISO methods.

Main Results:

• Increased moisture content observed in all formulations, reaching 13.21% in the 5% blend by day 14.
• Exponential fungal growth (10^2-10^4 CFU/g) correlated positively with moisture (r=0.87).
• Aflatoxin B1 detected from day 7, reaching 8.7 μg/kg in the 5% blend, exceeding EU limits (2 μg/kg).
• 15% cashew apple substitution showed antimicrobial effects, reducing fungal counts and aflatoxin B1 levels (4.1 μg/kg).

Conclusions:

• Cashew apple flour incorporation increases food safety risks due to mycotoxin development under uncontrolled tropical storage.
• Higher cashew apple content exhibits antimicrobial properties, potentially mitigating risks.
• Commercial viability requires strict moisture control (≤13%) and temperature regulation to meet food safety standards.